26 E Canadian Arctic Expedition, 1913-18 



EXPLANATION OF PLATE III. 

 Plate 2. Spruce from OopjJermine River forest, below Sandstone rapids. 



Fig. 1. Section showing work of Poly^raphus rujipennis Ky., beneath the bark. 



Fig. 2. Spruce toraiicli showing tunnels of Carphoborus andeirsoni Sw. 



Fig. 3. Spruce branch showing tunnels of Xylotrechus undulatus and Neoclytus mwicatulus. 



Fig. 4. Same as figure 3, the reverse side. 



